Add system76/launch_1 keyboard features

[jecassis]

Description

Implements the following changes for System76's Launch keyboard (launch_1):

• Disable mechanical locking support (LOCKING_SUPPORT_ENABLE) and switch state consistency with keyboard LED state (LOCKING_RESYNC_ENABLE) by default.
• Use TOTAL_EEPROM_BYTE_COUNT from AVR library for total size for portability.
• Start custom EEPROM region using EECONFIG_SIZE (mirrors how VIA does the same).
• Add README for default keymap.
• Remove custom Bootmagic Lite function and enable QMK's implementation in the Makefile.
• Update comments on almost all keyboard and keymap files.
• Allow removing System76 EC (i.e., configurator) functionality through a Makefile option (still enabled by default).
• Add header file for System76 EC to ease sharing between various System76 keyboards.
• Add key combination to unlock the keyboard and flash via System76 Firmware Updater (independent of QMK bootloader features).
• Update USB "multiplexer" and document code behavior in substantial detail. Check changes for consistency with the USB Type-C Port Controller Interface Specification.
• Enable removal of custom RGB matrix effects for space-saving (as implemented in Allow disabling RGB_MATRIX_ANIMATIONS on system76 keyboards with a pre-procesor directive #17478).
• Correct a couple of minor comment typos in core QMK files.
• Integrate and format changes from Move keyboard USB IDs and strings to data driven: S #17889 and Refactor legacy quantum keycodes in default-ish keymaps #17037.
• Update C formatting (using clang-format).
• Update copyright year.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by this PR

• None

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[PeterFalken]

@jecassis, FYI PR #17478 was merged recently.

[github-actions]

Thank you for your contribution!
This pull request has been automatically marked as stale because it has not had activity in the last 45 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, or re-open when it's ready.
For maintainers: Please label with bug, awaiting review, breaking_change, in progress, or on hold to prevent the issue from being re-flagged.

[PeterFalken]

@jecassis , I think that you only need to rebase this PR with master and that should take care of the conflicts.

[sigprof]

Apparently I forgot to click “Submit review” at the end, so my comment was left pending here for several months 🤦‍♂️

[github-actions]

Thank you for your contribution!
This pull request has been automatically marked as stale because it has not had activity in the last 45 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, or re-open when it's ready.
For maintainers: Please label with bug, awaiting review, breaking_change, in progress, or on hold to prevent the issue from being re-flagged.

[jecassis]

This PR has been ready to merge for a long while. All of the requested changes are implemented. Just waiting for final maintainer approval. @drashna can you please take a look and advise on how to proceed?

[github-actions]

Thank you for your contribution!
This pull request has been automatically marked as stale because it has not had activity in the last 45 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, or re-open when it's ready.
For maintainers: Please label with bug, awaiting review, breaking_change, in progress, or on hold to prevent the issue from being re-flagged.

[github-actions]

Thank you for your contribution!
This pull request has been automatically closed because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, or re-open when it's ready.
// [stale-action-closed]